306 PRESERVATION METHODS 



dian, American, English, and Russian workers report that this type of 

 storage room is very satisfactory for storing both unpackaged and/or 

 packaged seafoods^'^^"-^^'^". 



The jacketed system, as proposed by Canadian workers, consists of a 

 storage room placed within an insulated enclosure, with an air space 

 between the outside surfaces of the storage room and the inside of the 

 insulated walls. This annular space, referred to as the jacket, is lined 

 with wooden members to direct the flow of cooling air around the out- 

 side of the walls, ceiling, and floor of the storage area. The jacket is a 

 closed duct system containing a set of finned or bare-pipe cooling coils 

 and a fan to circulate the air. The cold air circulating through the jacket 

 ducts maintains the inner storage room at a predetermined temperature 

 by removing the heat migrating through the insulated walls, ceiling, and 

 floor before it can enter the refrigerated storage area. With proper air 

 flow, the difference between the temperature of the walls, ceiling, and 

 floor of the storage room and the heat of the storage room can be kept 

 as small as 2°F, making it possible to maintain relative humidities as 

 high as 98 per cent in the storage space. 



An experimental fully jacketed cold-storage room constructed by the 

 U.S. Bureau of Commercial Fisheries is shown in Figure 23.1. This room, 

 which was similar to that described above, operated quite satisfactorily, 

 maintaining relative humidities of 90 to 95 per cent. 



An experimental — 20°F jacketed cold store is being used at the Torry 

 Research Station, Aberdeen, Scotland. In this design, insulation is used 

 to form both the inner and outer surfaces of the jacket; whereas in the 

 Canadian and American installations insulation is used only on the outer 

 surfaces of the jacket and plywood or similar material is used on the inner 

 jacket surfaces, which comprise the walls, floor, and ceiling of the storage 

 room. Insulation of the inner walls of the room minimizes room temper- 

 ature fluctuations. 



In the Soviet Union, a large commercial six-story partially jacketed 

 cold store has been constructed. The plant has a total capacity of 27,240 

 tons of frozen products and 8,200 tons of chilled food. The outside walls 

 of each cold-storage room are jacketed, but the ceilings and floor are not. 

 The jacket for each storage room is two feet deep and contains refriger- 

 ated cooling grids. Natural circulation of air over the cooling coils results 

 in relative humidities of 97 per cent in the storage area. 



J.ITERATURE CITED 



1. Banks, A., Modern Htfriij., 54, 96(1951). 



2. Banks, A., Eddie, G. C, and Long, H. A. K., Modem Refrig., 57, 670(1954). 



3. Banks, A., Food Manuf., 29, 435(1954). 



